House electbic



Nov. 1,1927.

H. T. HERR BLEEDER TURBINE Filed June 1'7. 1925 2 Sheets-Sheet l INVENTOR I g H.T. H rr WITNESS ATTORNEY BY $0 9M Nov. 1 1927. 1,647,178

H. T. HERR BLEEDER TURBINE Filed June 1'7, 1925 2 Sheets-Sheet 2 H.T.Herr

lNVENTOR g- Pym ATTORNEY WITNES Patented Nov. 1, 1927.

UNITED STATES 1,647,178 di ries.

:rrnnnnnr 'r. HERE, on PHILADELPHIA, PENNSYLVANIA, ASSIGNOR 'ro we suits; nonsn ELECTRIC & MANUFACTURING COMPANY, A CORPORATION or PENNSYL- VANIA.

BLEEDER TURBINE.

Application filed .Tune 17, 1925. Serial No. 37,733.

My invention relates to fluid pressure turbines of the so-called bleeder type wherein steam or other fluid is extracted at various pressures for the purpose of feed water heat- 111g, process work, or for other uses.

in the accompanying drawings, Flg. l is a side view, in elevation, of a steam turbine constructed in accordance with one form of my invention; Fig. 2 is a transverse sectional view of the turbine shown in Fig. l on the line Iii-11 thereof; Fig. 8 is a fragmentary longitudinally sectional view of the structure shown in Figs. 1 and 2, being taken, for example, on the line IIIII1 of Fig. 2; Fig. 4 is a bottom view of the turbine shown in Fig. l with a portion of the cover plate broken away; Fig. 5 is a fragmentary sectional view similar to Fig. 2 and illustrating a modified form of my invention; Fig. 6 is a developed bottom view of a turbine casing constructed in accordance with the structure of Fig. 5; and Fig. 7 illustrates a modified form of fluid exit passage which may be used to advantage.

it is well-known to extract steam from a turbine at various pressures for the purposes of heating feed water in successive steps and for analogous uses, as fully set forth in U. S. patent to De Ferranti, No. 938,309, granted October 26, 1909. De F erranti points out the thermo-dynamic advantage of a large number of extraction points, but serious mechanical difficulties are encountered when it is attempted. to extract at a large number of points for the reason that the steam within a given turbine and at a given pressure is in the form of a relatively thin, annular band, as defined by the appropri ate stage. In attempting to extract steam at two pressures relatively close to each other, it is necessary to tap the two corresponding bands or zones of fluid within the turbine, and difficulties are encountered in the way of mechanical clearances, etc., in supplying the proper passage members for the extraction of steam from the relatively narrow zones and for its transfer to conduits of the usual type.

in accordance with my invention, I cast orotherwise mount a plurality of ribs on the exterior of the turbine casing, preferably the bottom thereof, said ribs coacting to define a grid. 1 then provide relatively long, narrow slots opposite the appropriate steam zones, one of said slots opening into each compartment of the grid. I then place a suitable cover member over the grid with openings therethrough into each of the compartments thus defined, attaching the extraction conduits in said openings.

Referring to the drawings for a more detailed understanding of my invention, I show a conventional turbine in Fig. l, the particular machine illustrated being of the well-known impulse reaction type having an impulse section at 11, a reaction section at 12, the latter comprising upper and lower casing members 13 and 14 and further having an exhaust connection 15. The reaction section includes a plurality of annular rows of blades wherein the steam is successively expanded, thereby dividing the steam into a series of relatively thin isobaric annuli. Steam is admitted to the impulse section 11 through a suitable conduit 16 under the control of a valve 17 It being desired to extract steam at, for

7 example, ten points in the reaction section,

1 provide the under surface of the lower casing member 14 with a grid of integral ribs, as shown at l8-18 in Figs. 2, 3 and 4. Said ribs are preferably sufliciently high so that the outer edges thereof may be machined to a surface of rotation having a ameter at least equal to that of the bolting flange 19-49. Thus interference of the members 19 with the tool is avoided.

Within the casing 12 is a spindle indicated at 20 in Fig. 3 having the well-known moving blades 2l-2l thereupon interleaved with suitable rows of fixed blades 2222, all as is well known and understood in the art. Opposite or before appropriate moving rows 21-21, relatively long, narrow slots 2323 are provided in the turbine casing, one of said slots opening into each of the grid compartments, as shown in Fig. 4-. By making said slots relatively long and narrow, each extracts steam only from the steam zone of a given stage, thus permitting extraction at a large number of points with the assurance that appropriate pressure difierences will be maintained between the respective slots, and without the necessity of unduly lengthening the whole turbine. Longitudinally adjacent slots are preferably disposed in staggered or ofiset relation forming two longitudinal rows of slots. This permits wider compart- 5. In a bleeder turbine, blading means wherein the motive fluid is expanded through a series of relativel thin isobaric annuli, a casing having a serles of adjacent, relatively long, narrow, peripheral bleeding slots therein, respectively disposed in radial alignment with certain of said annuli, integral reinforcing ribs on the bridges between adjacent slots and extending continu- 10 ously around each of said slots, a cover member secured to said ribs and coacting therewith to define a plurality of closed chambers, and conduit means tapping each of said chambers for translating the motive fluid escaping thereinto.

In testimony whereof, I have hereunto subscribed my name this eighth day of June, 1925.

HERBERT T. HERB. 

